function Hv=H(alpha, beta)
k=[cos(alpha)*cos(beta);
cos(alpha)*sin(beta);
sin(alpha)];

r{1} = [1/8 -1/8 0]; % Antenna's radius-vector, lambdas
r{2} = [-1/8 -1/8 0];
r{3} = [-1/8 1/8 0];
r{4} = [1/8 1/8 0];


phi=nan(4,1);

for i=1:4
    phi(i)=2*pi*r{i}*k;
end

Hv=exp(1i*phi);
end